| 摘要 |
PROBLEM TO BE SOLVED: To obtain a chemical agent capable of improving paper strength, paper manufacturing yield and freeness, by copolymerization of an N- vinylcarboxylic acid amide and acrylonitrile in specified proportions in the presence of polyvinyl alcohol(PVA) in an aqueous medium followed by conducting a hydrolysis. SOLUTION: This chemical agent for paper manufacturing is obtained by copolymerization of a monomer (mixture) composed of 10-100 (pref. 35-100)mol% of an N-vinylcarboxylic acid amide such as N-vinyl-formamide and 0-90 (pref. 0-65)mol% of acrylonitrile in the presence of PVA in an aqueous medium followed by conducting a hydrolysis. The weight ratio: PVA/monomer is pref. (2:1) to (1:20), and the intrinsic viscosity of the polymer resulted from the hydrolysis is pref. 0.1-10dL/g (in 1N saline solution). |
